Conventional hand-driven, wheeled carriers, such as shopping carts, strollers, walkers and wheelchairs, are not only always capable of carrying goods and human beings, but are also sometimes capable of stopping.
However, existing hand-driven, wheeled carriers can only switch between a free movement mode and a stop mode. Hence, they lack a mechanism for achieving deceleration as needed. For instance, users have to push harder the conventional hand-driven, wheeled carriers moving up a slope in order not to be overwhelmed by the conventional hand-driven, wheeled carriers. As a result, the conventional hand-driven, wheeled carriers pose a safety risk.
When it comes to a downward slope, the safety risk is even more intractable. Pulling the carriers while moving the carriers down the slope is a laborious job. Furthermore, a failure to catch a carrier rushing down a slope out of control is not uncommon among users, nor is it danger-free especially when the carriers are wheelchairs and strollers (whose riders are slower than average adults in responding.)